How do I cast a close vote on a question?

The current number of close votes will be shown under the question, in parenthesis, like so:

close (3)

If there are no close votes, it will simply say:

close

To cast a close vote -- or just to view the current count of close votes and reasons -- click the 'close' link under the question body. A list of close reasons, with descriptions and current counts, will appear.

If you wish to cast a vote at this point, use the radio buttons to specify a reason for closing the question, then click the "Vote to Close" button. If you select “off-topic”, you will need to select an additional sub-reason explaining why the question is off-topic.

It takes 5 close votes to reach the closing threshold (except for duplicate questions, which can be marked as duplicate with a single vote from a user who has earned a gold tag badge in one of that question's current tags, unless that user participated in editing the tags).

You may cast up to 24 close votes per day.

Close votes age away harmlessly if the threshold is not reached after a number of days. If the question has at least 100 views, close votes will age away after 4 days; otherwise close votes will age away after 14 days. Each new close vote resets the timer, so all close votes must be at least 4 or 14 days old respectively before aging occurs.

You can retract a close vote at any time if the question has not yet been closed by clicking on the 'close' link under the question. This will display the standard close dialog, with the submit button changed to a 'Retract Vote' button.

What happens when a question is closed?

Once a question has been closed, it will no longer accept new answers and the words [on hold] will be appended to the title. After 5 days, if the question remains closed, the word [closed] will instead be appended to the title.

Closed questions can be reopened through a similar voting process. The current number of reopen votes will be shown as current under the question, in parenthesis, like so:

reopen (3)

A tooltip displays the number of votes required to reopen. If there are no reopen votes, it will simply say:

reopen

Questions can go through multiple close and reopen cycles, but each individual user may cast at most one close and one reopen vote per question.

Closed questions may be merged with another question, migrated to another site in our network, or even deleted.

Alternatives to closing

If the question has serious problems (e.g. it is spam or offensive), flag it instead.

If you don't have enough reputation to cast close votes, you can also flag for closure.

If you have used up your close votes for the day and the question is a duplicate, post a comment with a link to the original.

Reviewing close and reopen votes

This privilege level unlocks two review queues for questions that may need to be closed or reopened.

Any post which currently has an active close vote or a close flag will appear in the Close Votes review queue. In this queue, users can either vote to close the question, edit the question, or recommend leaving it open. Edits or a sufficient number of "Leave Open" reviews will remove the question from review and immediately begin aging the close votes. If the question receives another close vote after being kicked out, it will re-enter the queue for further review. Questions with vote to close as a duplicate will also list each possible duplicate in a tab at the top for easy reviewing.

Similarly, the reopen queue will contain any post that currently has an active reopen vote. Users can vote to reopen, edit the question (which includes a reopen vote), or leave the question closed. A certain number of Leave Closed votes will again kick the question out of the queue and begin the reopen vote aging process, and of course, another reopen vote will put it back into the queue. Questions which get edited within 5 days of being closed will automatically show up in the reopen queue for review. Questions which have had a revision will add an extra tab at the top so that you can quickly view the revision. Like the close votes queue, questions which were closed as duplicates will still list the duplicates in the tabs above.